Hippopotamus, (plural: hippopotamuses or hippopotami), a large animal found in tropical Africa. Its name comes from the Greek for “river horse,” although the hippopotamus is related to the hog rather than the horse. It spends most of its time in or near freshwater, but will travel inland in search of food.

The hippopotamusThe hippopotamus lives throughout tropical Africa.
Species of Hippopotamuses
The Common Hippopotamus

is one of the largest of all animals. A bull (male) hippopotamus may be 5 feet (1.5 m) high at the shoulder and 12 feet (3.7 m) long, and may weigh up to 4 tons (3,630 kg). Its legs are short and thick, and its round body almost touches the ground when it walks. Its wide, four-toed feet have heavily padded soles.

The hippopotamus has a large head and short neck. Its nostrils are on top of its wide, rounded muzzle, and its eyes and ears are set high on its head. It can submerge all of its body for long periods, with only the nostrils, eyes, and ears above water. From time to time, it will lift its head and open its huge mouth, showing long tusks curving up from the lower jaw. The lower pair of central incisors project forward as smaller tusks. The hippopotamus can submerge its head entirely for several minutes by closing the valves of its nostrils. When it surfaces, it blows out a moist spray and sometimes gives a loud roaring snort.

The hippopotamus has dark-brown skin that is hairless except for a few bristles on its muzzle and ears, and at the end of its short tail. The skin, l 1/2 inches (4 cm) thick on the back and sides, sometimes secretes an oily pink liquid.

The Pygmy Hippopotamus

is found only in Liberia and Sierra Leone. It is seldom more than 2 1/2 feet (75 cm) high and weighs about 400 pounds (180 kg). It has a proportionately smaller head and longer legs, and spends more of its life on land than does the common hippopotamus. Otherwise, it is similar to its larger relative in appearance and habits.

Habits of the Hippopotamus

Hippopotamuses live in herds of 20 to 30. They are not aggressive, but are dangerous fighters if frightened or attacked. They are not fast swimmers, but on land can run as fast as a man. The female (cow) bears one or, rarely, two calves a year. Hippopotamuses live for 30 years or more.

Hippopotamuses feed at night, mostly on grass and water plants. They often ruin crops by eating large amounts of growing plants and trampling others underfoot. Some African tribes prize hippopotamus meat as food and use the skin for various purposes. The tusks are valued as ivory.

How Does a Hippo Lend a Helping Hoof?

A hippo’s hoof has four webbed toes. The webbing makes it easier for the hippo to walk in water. As hippos step, their hoofs stir up mud on the bottom of the lake or the river. Fish eat the creatures that the hippos dig up as they move along.

The hippo helps animals in other ways, too. It opens its mouth and lets one kind of fish eat food that is stuck in between its teeth. In return, the fish clean the hippo’s skin by eating algae (AL jee), or tiny, plantlike bacteria, that collect on it.

Sometimes geese and other water birds help hippos, too. They sit on the hippo’s back and eat insects off its skin.

Hippopotamuses make up the family Hippopotamidae. The common hippopotamus is Hippopotamus amphibius; pygmy, Choeropsis liberiensis .